BACKGROUND: To evaluate the incidence of asymptomatic deep vein thrombosis (DVT) in Chinese after cesarean section (CS). METHODS: This is a prospective observational study. Ethnic Chinese women who were asymptomatic for DVT and delivered by CS were included. Duplex ultrasound scan (US) of the lower limbs was carried out 3-7 days after CS. RESULTS: From July 2000 to March 2001, a total of 93 women were examined. The mean age was 32.1 years (SD 5.0). Forty-nine of 93 CSs were elective (52.7%). The median time from CS to US was 4 days (interquartile range, 4-5 days). No case of DVT was found in these 93 women. CONCLUSION: The incidence of asymptomatic DVT is low in Chinese women after CS. Routine screening for DVT after CS is not warranted.